The present invention relates to electronic devices, for example, a semiconductor integrated circuit device (hereinbelow, termed "IC").
In recent years, as the packaging density has been rendered higher and higher in bipolar ICs and related devices and as the wiring has become multilayered, organic polymer insulator films such as polyimide resin films, which are excellent in thermal resistance, micro-workability, etc., have come into frequent use as inter-layer insulating films or passivation films. An example in which a polyimide resin is employed for the interlayer insulating film of multilayer wiring is disclosed in the Official Gazette of Japanese Laid-Open Patent Application No. 55-150254. The inventor of the present application has experimented with such a resin-molded IC wherein a chip is encapsulated in a molded resin with the chip comprising a plurality of semiconductor elements which are formed in one major surface of a semiconductor substrate, Al wiring leads which connect the semiconductor elements electrically, and the aforementioned interlayer insulating film which is made of the polyimide resin. From these experiments, the inventor has found that the moisture-proofing of the device deteriorates in the vicinity of the periphery of the chip (approximately 40-50 .mu.m from the peripheral edge), and water intrudes into the chip through this part, so the first layer of Al wiring is liable to corrosion. As the cause of such deterioration of the moisture-proofing of the device, the inventor has determined that the polyimide resin binds poorly with a phosphosilicate glass (PSG) film or oxide (SiO.sub.2) film which is formed on the major surfaces of the semiconductor substrate. This poor binding leads to a great external stress (e.g., 60 kg/cm.sup.2) which acts on the IC chip due to the curing of a resin in the resin molding operation to create a separation of the polyimide resin in the peripheral part of the chip. The "separation" is the state of inferior adhesion which develops in such a manner that the soft polyimide resin becomes distorted, shifts or comes off at its interface with the underlying hard SiO.sub.2 -based film. As the multilayer wiring of the semiconductor chip is increasingly built up, this chip becomes more liable to the stress due to the shrinkage of the molded resin, and the separation of the resin film in the peripheral part becomes more conspicuous.